23 Foods That Boost Immune System

April 6, 2015

Your ability to interact with the world around you and remain healthy is dependent to a large extent on the healthy functioning of your immune system. Your immune system is responsible for fighting foreign invaders to your body, like pathogenic bacteria and viruses, and also for destroying cells within your body when they become cancerous. Poor nutrition has been shown to result in increased infections, to slow healing from injury and infections, and to increase susceptibility to symptoms and complications from immune system dysfunction. Science has shown that immune function often decreases as we age, and recent research suggests this decrease is also related to nutrition and may be slowed or even stopped by maintaining healthy nutrition.

One of the most important steps you can take to maintain good health is to eat a healthy diet loaded with foods that boost immune system.

Foods That Boost Immune System

1. Coconuts and Coconut Oil

Besides being excellent for your thyroid and your metabolism, coconut oil is rich in lauric acid, which converts in your body to monolaurin. Monolaurin is the actual compound found in breast milk that strengthens a baby’s immunity.

A great deal of research has been done establishing the ability of lauric acid to enhance immunity. This medium-chain fatty acid (MCFA) actually disrupts the lipid membranes of offending organisms

When selecting coconuts and coconut oil, make sure you choose organic ones that are unrefined, unbleached, made without heat processing or chemicals, and are non-GMO.

2. Yogurt

Probiotics, or the “live active cultures” found in yogurt, are healthy bacteria that keep the gut and intestinal tract free of disease-causing germs. Although they’re available in supplement form, a study from the University of Vienna in Austria found that a daily 7-ounce dose of yogurt was just as effective in boosting immunity as popping pills. In an 80-day Swedish study of 181 factory employees, those who drank a daily supplement of Lactobacillus reuteri—a specific probiotic that appears to stimulate white blood cells—took 33 percent fewer sick days than those given a placebo.

3. Mushrooms

Mushrooms strengthen your immune system because they are rich in protein, fiber, vitamin C, B vitamins, calcium, and other minerals.

Mushrooms make up a large part of the fabric of the earth. According to Paul Stamets, one of the world’s leading authorities on the health benefits of mushrooms, one cubic inch of soil can contain eight miles of mycelium.

Mushrooms also contain powerful compounds called beta-glucans, which have been long known for their immune enhancing properties. The beta-glucans in medicinal mushrooms (especially Reishi, Shiitake, and Maitake) are notable for their ability to activate/modulate your immune system.

Beta-glucan enhances immunity through a variety of mechanisms, many of which are similar to those of echinacea or astragalus root. For example, it binds to macrophages and other scavenger white blood cells, activating their anti-infection activities. Numerous studies support this.

4. Oats and Barley

These grains contain beta-glucan, a type of fiber with antimicrobial and antioxidant capabilities more potent than echinacea, reports a Norwegian study. When animals eat this compound, they’re less likely to contract influenza, herpes, even anthrax; in humans, it boosts immunity, speeds wound healing, and may help antibiotics work better.

5. Garlic

This potent onion relative is one of the foods that boost immune system, and contains the active ingredient allicin, which fights infection and bacteria. British researchers gave 146 people either a placebo or a garlic extract for 12 weeks; the garlic takers were two-thirds less likely to catch a cold. Other studies suggest that garlic lovers who chow more than six cloves a week have a 30 percent lower rate of colorectal cancer and a 50 percent lower rate of stomach cancer.

6. Sweet Potatoes

You may not think of skin as part of your immune system. But this crucial organ, covering an impressive 16 square feet, serves as a first-line fortress against bacteria, viruses, and other undesirables. To stay strong and healthy, your skin needs vitamin A. “Vitamin A plays a major role in the production of connective tissue, a key component of skin,” explains Prevention advisor David Katz, MD, director of the Yale-Griffin Prevention Research Center in Derby, CT. One of the best ways to get vitamin A into your diet is from foods containing beta-carotene (like sweet potatoes), which your body turns into vitamin A.

7. Ginseng

It’s not clear how the root of the ginseng plant works, but claims on behalf of Asian ginseng are many, including its ability to stimulate immune function. Despite the claims of a number of mainly small studies, the National Center for Complementary and Alternative Medicine (NCCAM) considers there have been insufficient large studies of a high enough quality to support the claims. NCCAM is currently supporting research to understand Asian ginseng more fully.

8. Broccoli

Broccoli is super-charged with an arsenal of vitamins and minerals ready to do battle with any germ or infection. Packed with vitamins A, C, and E, as well as numerous antioxidants, broccoli is one of the healthiest vegetables you can put on your table. The key to keeping its power intact is to cook it as little as possible, or better yet, not at all.

9. Beef

Zinc deficiency is one of the most common nutritional shortfalls among American adults, especially for vegetarians and those who’ve cut back on beef, a prime source of this immunity-bolstering mineral. And that’s unfortunate, because even mild zinc deficiency can increase your risk of infection. Zinc in your diet is very important for the development of white blood cells, the intrepid immune system cells that recognize and destroy invading bacteria, viruses, and assorted other bad guys, says William Boisvert, PhD, an expert in nutrition and immunity at The Scripps Research Institute in La Jolla, CA.

10. Citrus

Most people turn to vitamin C after they’ve caught a cold. But did you know it tops the charts of foods that keep your immune system running at 100%? Vitamin C helps increase the production of white blood cells, key to fighting infections. Because your body doesn’t produce or store it, daily intake of vitamin C is essential for continued health. Almost all citrus fruits are high in vitamin C and with such a variety to choose from it’s easy to add a squeeze of C to any meal.

11. Chicken Soup

It turns out there is something to chicken soup after all. In one study, hot chicken soup was more effective than hot or cold water at making noses run—a good thing since nasal secretions help rid the body of pathogenic viruses and bacteria. Like any hot liquid, soup also helps you to stay hydrated and raises the temperature of the airways, both of which are important for loosening secretions. Adding a few hot chiles to this Chicken Noodle Soup with Dill recipe might help loosen things up even more.

12. Licorice Root

Licorice root is used in Chinese medicine to treat a variety of illnesses. Most studies of licorice root have been done in combination with other herbs, so it’s not possible to verify whether any effects were attributable to licorice root per se. Because of the potential side effects of taking licorice and how little is known about its benefits — if any — for stimulating immune function, this is an herb to avoid.

13. Green Tea

Polyphenols, potent plant antioxidants, are what’s believed to give green tea its immune-boosting effects. One laboratory study suggested that a particular type of polyphenols called catechins may kill influenza viruses. To maximize benefits and minimize bitterness, use just-below-boiling water and steep green tea no more than a minute or two. A little lemon and honey can also help blunt the bitterness. But don’t add milk, because the proteins will bind to the polyphenols, making them ineffective.

14. Red Bell Peppers

Vitamin C not only boosts immune systems but it helps maintain healthy skin, which is the frontline in our war on colds. Think citrus fruits have the most vitamin C of any fruit or vegetable? Think again. Ounce for ounce, red bell peppers have twice as much flu-fighting vitamin C, as well as being a rich source of beta carotenes.

15. Turmeric

A key ingredient in many curries, this bright-yellow, bitter spice has been used for years as an anti-inflammatory in treating both osteoarthritis and rheumatoid arthritis. High concentrations of curcumin, which gives turmeric its distinct color, have been shown to contain strong flu and cold fighting properties.

16. Carrots

Carrots are an excellent source of beta-carotene, which gives them their bright color. One of beta-carotene’s jobs is to support the body’s mucus membrane, which lines the respiratory and intestinal tracts, making it harder for bacteria to enter the bloodstream and cause trouble. For a healthy diet, enjoy raw carrots along with cauliflower, broccoli, and other veggies as an appetizer. You can also pickle them or steam and puree them with some broth for a rich soup — a soothing meal when you’re sick.

17. Ginger

Ginger is another ingredient many turn to after they’ve caught a cold. But like vitamin C, ginger can also help you prevent that cold from taking hold in the first place. While it’s used in many sweet desserts, ginger packs some heat in the form of gingerol, a relative of capsaicin, which gives chili peppers their distinctive heat. Ginger may help decrease chronic pain and may possess cholesterol-lowering properties.

18. Cinnamon

Cinnamon is an antiviral, antifungal, and antibacterial machine, so it does more than just boost the immune system — it actually fights the pathogens that cause illness. Cinnamon is extremely versatile, making it easy to add to your healthy diet. You can mix it into your coffee grinds for an immunity-fighting brew, add it to tea, sprinkle it on oatmeal, stir it into hot chocolate, or dust it onto fresh fruit.

19. Almonds

When it comes to preventing and fighting off colds, vitamin E tends to take a backseat to the more commonly mentioned vitamin C, but vitamin E is also key to a healthy immune system. Vitamin E is a fat-soluble vitamin, meaning it requires the presence of fat to be absorbed properly. Almonds are packed with vitamin E and a half cup serving provides nearly 100% of the daily recommended amount.

20. Kale

Greens such as kale, spinach, and Swiss chard are immune-boosting foods that contain high levels of vitamin C, which not only packs a powerful antioxidant punch, it helps fight off infection and regenerate other antioxidants in the body, including vitamin E. They also contain folate, another immune booster. Sautée kale, spinach, or Swiss chard with garlic and olive oil, or use fresh spinach to make an nutrient-rich salad — top it with fresh mushrooms to pack an extra immune-boosting punch.

21. Watermelon

Watermelon is one of the foods that boost immune system. Once considered only a summertime treat, this immunity boosting food may also help ward off winter’s ills. Like other fruits, watermelon is packed with vitamins, minerals, and other nutrients, but what makes it a super food is its large concentration of lycopene. Lycopene gives watermelon flesh its red color and offers an array of health-building benefits, including reducing respiratory inflammation, which helps prevent infection. If possible, make watermelon part of your healthy diet year round.

22. Spinach

Spinach made our list not just because it’s rich in vitamin C but because it’s packed with numerous antioxidants and beta-carotene, which have been proven to increase the infection-fighting cells of our immune systems. Similar to broccoli, it is one of the foods that boost immune system and best cooked as little as possible so that its nutrients are retained.

23. Wheat Germ

Wheat germ is a key source of fiber — a dietary essential that keeps your digestive system on track. It’s also packed with protein and vitamins, including vitamin E, and is a great source of choline and zinc, which also help boost immunity. Add wheat germ to your bread, muffin, and cookie recipes, dust it on fish instead of bread crumbs, or sprinkle it over yogurt and fresh fruit or your breakfast cereal.